Artillery, or large caliber guns of the kind of interest for present purposes are, in general, guns larger than those intended to be transported and operated by one man. Such guns, in general, include a carriage or frame, which enables the azimuth and elevation to be adjusted and which, during firing, is held stationary. Normally, the barrel of the gun is mounted for limited axial movement relative to the frame, so that, upon firing, the gun recoils and moves backward relative to the frame. Before the gun can be fired again, the backward movement must be stopped, the gun must be reloaded and the barrel returned to its forward, firing position. The firing of the gun releases a great deal of energy some of which inevitably appears as the kinetic energy of the rearward motion, or recoil, of the gun barrel. In order to stop such rearward motion, this energy must be dissipated and/or stored and/or utilized, and equipment for these purposes is normally provided. Such equipment may vary widely in kind and in complexity. One arrangement includes a pair of hydraulic cylinders and pistons with one element of each pair, for example, the cylinders, fastened on opposite sides of the gun barrel and with the other element of each pair fastened to the frame. Hydraulic circuitry connects the cylinder to an accumulator so that, during recoil, fluid from the cylinders flows to the accumulator thereby storing the energy of recoil. This recoil equipment may be supplemented by snubbers such as springs, rubber bumpers, 10 dashpots and the like. The stored energy may be used to reload the gun and/or to return it to its firing position.
Equipment such as that briefly described above has been widely used but has been subject to a number of limitations and disadvantages. Recently there has been considerable activity in the design of improved equipment to overcome these limitations and disadvantages. However, the testing of such newly designed equipment presents numerous difficulties. A runout and recoil control system may, of course, be tested for the first time by installing the system on the gun and then firing the gun but such a procedure is not attractive. For one thing, there are usually severe restrictions regarding the time, the places and the conditions under which the gun may be fired. Compliance with the conditions is often time consuming and expensive. Furthermore, reliance on a previously untested system to control recoil raises serious questions as to the safety of both personnel and equipment.
It is a general object of the present invention to provide an improved method and apparatus for testing and evaluating systems and equipment for controlling the runout and/or recoil of a gun.